The value of the UK food and grocery market is to soar by a fifth to a record £206bn by 2018, according to new research, with online sales doubling and big increases in business for convenience stores and food discounters such as Aldi and Lidl.

The latest findings from the food and consumer research and training charity IGD indicate that in five years time those three sales channels will account for more than £3 out of every £4 of growth in UK grocery.

Online and convenience retailing are the main beneficiaries of consumers' growing reliance on smartphones and tablets which are now revolutionising the way we shop – even for perishable goods and those needing cold storage. While superstores and hypermarkets still generate the most sales of any type of grocery format in terms of volume, they will grow at a considerably slower rate in comparison with these three formats. Large supermarkets or superstores and hypermarkets now account for sales of £74.1bn and are set to grow by a sluggish 8.2% to £80.1bn by 2018. The IGD forecasts* underline why Tesco is scaling back its plans to open big new stores.

The UK food, grocery and drink sector is currently worth £170bn but is set to grow in value by 21% to nearly £206bn, IGD forecasts. Online sales – currently worth only £6.5bn – will more double in value (increasing by some 124%) to nearly £15bn, the latest figures reveal. The second fastest growth is predicted to be in sales through food discounters – currently worth £9.5bn but nearly doubling by 96.3% to £18.6bn.

Joanne Denney-Finch, chief executive of IGD, said: "The 'hot three' areas of online, convenience and food discounters are the ones to watch."

She said online and convenience retailing were "reaping the rewards of our changing lifestyles. With more of us owning smartphones and tablets, online grocery shopping is becoming more popular. Retailers are also introducing more convenient and flexible services, such as temperature controlled 'click & collect' lockers for shoppers to pick up their groceries at a time and place that suits them."

Convenience stores in the heart of towns and other communities are also benefiting from the cultural shift towards shopping "little and often", Denney-Finch said: "They are increasingly providing products tailored to specific locations rather than a 'one size fits all' approach.

"With their sales set to rise by over £10bn over the next five years, we're forecasting convenience to bring in the biggest cash growth of any type of grocery retailing between 2013 and 2018.

"We also expect food discounters, like Aldi and Lidl, to continue to do well and build on their recent stellar performance. They have improved shopper perceptions by effectively communicating the quality and value for money of their products while also expanding the range of items they sell to help shoppers complete more of their weekly shop there. Nearly a third (32%) of shoppers tell us they will use food discounters more in the year ahead compared to almost a quarter (24% in September 2010)."

*IGD's shopper research is from IGD Shopper Vista — a monthly analysis involving questions put to a panel of 1,000 shoppers.